Mandolin · ninth
A9 Chord on Mandolin
A Dominant 9th is A, C#, E, G, B — the 1-3-5-b7-9 pattern of a ninth chord. Here is the shape, the audio, and what usually goes wrong.
There is no open A9 on mandolin — the single shape below is a barre, which is exactly why this chord trips people up. Take it slowly and check every string.
Start here — Movable 9th Shape (4th fret)
Barre at fret 4 — harder to hold than an open shape, but movable: slide it and you have every other ninth chord.
What beginners get wrong
Moving in and out of it
The shape above: Movable 9th Shape (4th fret) — barred at fret 4.
Listening: each shape above has its own play button, and each one plays the notes that shape actually produces — not a generic triad.
A9 on other instruments
Same notes, different hands. Every link below is a real page with diagrams and audio.
Chords next door
Same root, different colour — and all of them playable on mandolin.
A9 on Mandolin — questions people ask
What is the easiest way to play A9 on mandolin?
“Movable 9th Shape (4th fret)” — which we rate advanced — is the easiest A9 shape on mandolin. Barre at fret 4 — harder to hold than an open shape, but movable: slide it and you have every other ninth chord. There is no open A9 on mandolin, so a barre is unavoidable; this is the least demanding one.
What notes are in the A Dominant 9th chord?
A Dominant 9th is A, C#, E, G, B — the 1-3-5-b7-9 interval pattern of a ninth chord. Every voicing on this page uses those notes and nothing else; they just appear in a different order and octave.
What can I play instead of A9?
The nearest stand-ins on mandolin that keep the same root are Asus4, Asus2, A. They keep the root and the fifth and only change what sits in the middle, so most songs still work — but check the swap against the melody, because the note you removed may be the one the tune is singing.
Can I play A9 on other instruments?
Yes. A9 is the same set of notes everywhere; only the fingering changes. This site has diagrams and audio for it on guitar, piano, ukulele.
Learn the theory behind A9
The shape gets your fingers there. These explain why it sounds the way it does.
Barre Chords — The Wall Every Guitarist Climbs
This one asks for a barre. The article is the fix for the buzzing and the aching hand.
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Functional Harmony: Three Roles, One Engine
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The 12-Bar Blues — Three Chords, A Century of Hits
Seventh chords are the whole sound of the blues. Twelve bars is where to hear it.
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